The way through I see past/future,
First of all calm yourself down,
Then visualize yourself in a quite place like desert, mountains, then visualisation a room/house and go into that house,room , close the door and forget everything of out side and visualise that room/house is alone in dark/light and make as perfect visualisation as you can do, of that room/house, if you visualized a house then go in a room and visualise there is a big screen and a remote on a sofa/couch and make yourself believe that the room takes you to the past /future and screen is a way to go into that time, and it show you places where you want to go by using that remote or you can do it without remote, you may do many things if you done that right, like you can meet your spiritual self, spiritual guide etc
Other way to see past/furture.
First of all, Calm yourself down
Some exercises were used to calm down are: breathing exercise, alpha state meditation, sitting calmly without any thoughts running in mind.
Sit or lay down, in a room or anywhere in your house where you'll likes to meditate, or feels quite or protected,
Then visualize white light or any protective light which makes you feel protected around you filling your whole room , now visualize yourself getting out of your body and stand out , now go out of the room/ house which you will already protected with light, close the door and forgot about everything, now look forward visualize everything is white/black or you can also visualize a jungle ran and feel the breeze, your legs, everything, every moment and different time, now try to make yourself comfortable with that time and try to run faster and go out of that place. When you're out of that place you're on past/future,.
It will all works according to your own beliefs, favorites, senses , pictures in your mind about what you'll gonna see in respected time.